A little discuss around fuel economy and what you should expect from your cars even before acquiring the. Engine technology alongside engine capacity is what you have in numbers on the rear of the cars. 1.0L, 2.0L, 3.0L…7.0L. The higher the number, the more the power your car has and more so, the more fuel it would consume. Several car makers use the same engine for several car makes. This is to make life easier for everyone especially in maintenance of the vehicles. It basically implies that a technician that fixes one would definitely fix the others. A car with 2.0L engine would be more fuel efficient but slower than another with 3.0L engine.
Sister companies (like Toyota and Lexus; Nissan and Infinity) would run the same engines in several of their vehicles and even let other car makers use those same engines in their productions with agreement of course. The differences in acceleration or agility, pace and performance will depend on other factors.
A little analysis here; if Hussein Bolt did 100metres in 9.58 seconds, it would take him longer if you gave him a school bag with books and let him take the same distance again. He would be more stressed as well. Weight added makes the car engine do more work at moving the car which implies that it would take more fuel with more weight. Tyres will suffer more too because of the weight.
Using Lexus and Toyota who are sister companies in this analogy. The 2005 Avalon, 2008 Highlander, 2007 V6 Camry, and the Lexus ES 350, RX350 all carry the same 3.5L V6 engine. They will not consume the same amount of fuel for the same distances because of the difference in design (how aerodynamic everyone is) and the weight differences. The heavier one will definitely be less fuel efficient. Seeing a biker bending his head into the fore of his bike is him trying to be more aerodynamic to achieve speed faster while being more fuel efficient. A runner who bends his head is trying to achieve the same feats. I would expect the Toyota Camry to be more agile than the heavier Avalon though they have the same engine.
Basically, the more weight your car has on, the more work the engine does and the more fuel it would consume and absolutely the more wear it will experience. It is the reason some cars would wear out faster than others of the same make.